Tier 1 Dependent visa after main application naturalised

Hi experts.

I have a same situation
My wife got her visa in Aug 2013 and entered in UK first time on Sep 2013
Her first extension done on Oct 2014. So currently she is on tier 1 general dependent visa which is valid till OCT 2017.
Meanwhile i got ILR and last month got naturalised as British citizen.
I understand she will continue to extend her visa on Tier 1 General Dependent

But I have couple of questions regarding the current form i.e "Application to extend stay in the UK as Tier 1 or 5 dependant"

In Section C – Details about the PBS main applicant you are dependent on

C3; What is the nationality of the PBS main applicant you are dependent on, as stated in
their passport or travel document?

so my natinality was Pakistani that time should I mentioned Pakistani or British as I am British Citizen as well now (I have dual nationalities).

C4; What is the reference number for the most recent application of the PBS main applicant
you are dependent on?

Do I need to give the naturalised as British Citizen application refrence number (which is the latest one)?
OR
Do I need to give the ILR application refrence number?
OR
The last time I extend my visa under Tier 1 (General)?

Thanks in advence

Regards

Why are you worrying about this now, some 18 months before she is due for an extension?

thanks for your reply CR001.

I want to prepare myself as I understand right or not? and if I am right so what would be the answer of these queries.

This also help others who are in a process of applying extension for their dependents.

Regards

I don't understand why people try to read between the lines!!

C3: Note the use of "is".
C4: Note the use of "most recent".

Simple English, with simple meaning!!